New family of free-fluoride synthetic clay was synthesized via solution route. All starting solutions were made by applying carbon tetra-chloride (CCl4) as a solvent. The selected sample of synthetic free fluoride–Na-4-mica was having the general formula (Na4Mg6M4Si4O22.nH2O) where M = Cr3+ was exposure to two different É¤-irradiation doses 1st dose = 1.5 MR/h and 2nd dose = 3 MR/h at 25 cm distance. Structural parameters such as lattice constants, volume and phase quality were monitoring carefully by using both of XRD and SEM evaluating grain size of the mica bulk. Structural investigations proved that Cr-clay exhibits monoclinic phase accompanied with structure quality in comparison with both of Bi-and Al-clays.